Preparation of chitosan functionalized end‐capped Ag‐NPs and composited with Fe3O4‐NPs: Controlled release to pH‐responsive delivery of progesterone and antibacterial activity against pseudomonas aeruginosa (PAO‐1)

In this work, functionalized chitosan end‐capped Ag nanoparticles (NPs) and composited with Fe₃O₄‐NPs was prepared as pH‐responsive controlled release carrier for gastric‐specific drug delivery. The structure of prepared material was characterized by FE‐SEM, XRD, EDS and FT‐IR analysis. The loading behavior of the progesterone onto this novel material was studied in aqueous medium at 25°C and their release was followed spectrophotometrically at 37°C in seven different buffer solutions (pH 1.2, 2.2, 3.2, 4.2, 5.2, 6.2 and 7.2) to simulate intestine and gastric media which experimental results reveal more release rate in pH 1.2 (gastric medium) with respect to other buffers. This observation is attributed to dependency of the CS‐IMBDO‐Ag‐Fe₃O₄‐NPs and progesterone structure with buffer pH that candidate this new material as prospective pH‐sensitive carrier for gastric‐targeted drug delivery. On the other hand, the antibacterial properties of this material against gram‐negative bacterium pseudomonas aeruginosa (PAO‐1) in agar plates was studied and accordingly based on broth micro dilution the minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) with respect to standard CLSI in different concentrations of CS‐IMBDO‐Ag‐Fe₃O₄‐NPs was calculated. The results reveal that MIC and MBC values are 50 and 1250 μg/mL, respectively. In addition, extracts of Portulaca oleracea leaves was prepared and its antibacterial activity in single and binary system with CS‐IMBDO‐Ag‐Fe₃O₄‐NPs as synergies effect against PAO‐1 was tested and results shown that these materials have significant synergistic effect for each other.     

Physiochemical properties and novel biological applications of Callistemon viminalis‐mediated α‐Cr2O3 nanoparticles

We report an eco‐friendly synthesis of α‐Cr₂O₃ nanoparticles (NPs) using Callistemon viminalis (Bottle Brush) flower extracts as an efficient reducing and capping agent. NPs of sizes 15 nm and 17 nm were synthesized by annealing them at 400°C and 500°C, respectively, which were characterized by X‐ray diffraction, UV–Vis, Fourier transform‐infrared, high‐resolution‐transmission electron microscopy/scanning electron microscopy, SAED, energy‐dispersive X‐ray spectroscopy and SQUID. Microplate‐based assay was used for examining antibacterial potential against 12 pathogenic bacterial strains, and their minimum inhibitory concentrations were calculated. MTT cytotoxic assay was accomplished on Leishmania tropica amastigotes and promastigotes, which revealed IC₅₀ values of 44 μg/ml and 10.56 μg/ml, respectively. An IC₅₀ value of 46.32 μg/ml was obtained for HepG2 cancer cells. Enzyme inhibition studies indicated good acetylcholinesterase, moderate butyrylcholinesterase and low alpha‐glucosidase inhibition. Hemolytic assay indicated hemocompatibility at low concentration. In addition, good DPPH radical scavenging and moderate reducing power and total antioxidant potential was revealed by α‐Cr₂O₃ NPs.     

Surface-modified TiO(2) nanoparticles as affinity probes and as matrices for the rapid analysis of phosphopeptides and proteins in MALDI-TOF-MS

We utilized three different types of TiO₂ nanoparticles (NPs) namely TiO₂‐dopamine, TiO₂‐CdS and bare TiO₂ NPs as multifunctional nanoprobes for the rapid enrichment of phosphopeptides from tryptic digests of α‐ and β‐casein, milk and egg white using a simplified procedure in MALDI‐TOF‐MS. Surface‐modified TiO₂ NPs serve as effective matrices for the analysis of peptides (gramicidin D, HW6, leucine‐enkephalin and methionine‐enkephalin) and proteins (cytochrome c and myoglobin) in MALDI‐TOF‐MS. In the surface‐modified TiO₂ NPs‐based MALDI mass spectra of these analytes (phosphopetides, peptides and proteins), we found that TiO₂‐dopamine and bare TiO₂ NPs provided an efficient platform for the selective and rapid enrichment of phosphopeptides and TiO₂‐CdS NPs efficiently acted as the matrix for background‐free detection of peptides and proteins with improved resolution in MALDI‐MS. We found that the upper detectable mass range is 17 000 Da using TiO₂‐CdS NPs as the matrix. The approach is simple and straightforward for the rapid analysis of phosphopeptides, peptides and proteins by MALDI‐MS in proteome research.     

Environmentally friendly and highly efficient synthesis of benzoxazepine and malonamide derivatives using HPA/TPI‐Fe3O4 nanoparticles as recoverable catalyst in aqueous media

A magnetic inorganic–organic nanohybrid material (HPA/TPI‐Fe₃O₄ NPs) was produced as an efficient, highly recyclable and eco‐friendly catalyst for the one‐pot multi‐component synthesis of malonamide and 2,3,4,5‐tetrahydrobenzo[b ][1,4]oxazepine derivatives with high yields in short reaction times (25–35 min) in aqueous media at room temperature. The nanohybrid catalyst was prepared by the chemical anchoring of H₆P₂W₁₈O₆₂ onto the surface of modified Fe₃O₄ nanoparticles (NPs) with N ‐[3‐(triethoxysilyl)propyl]isonicotinamide (TPI) linker. The magnetic recoverable catalyst was easily recycled at least ten times without any loss of catalytic activity.     

Bioinspired synthesis of multifunctional silver nanoparticles for enhanced antimicrobial and catalytic applications with tailored SPR properties

In the developing nanotechnology world, numerous attempts have been made to prepare the nobel metallic nanoparticles (NPs), which can improve their applicability in diverse fields. In the present work, the biosynthesis of silver (Ag) NPs has been successfully achieved through the medicinal plant extract (PE) of G. resinifera and effectively used for the catalytic and antibacterial applications. The size dependant tuneable surface plasmon resonance (SPR) properties attained through altering precursor concentrations. The X-ray and selected area diffraction pattern for Ag NPs revealed the high crystalline nature of pure Ag NPs with dominant (111) phase. The high-resolution TEM images show the non-spherical shape of NPs shifting from spherical, hexagonal to triangular, with wide particle size distribution ranging from 13 to 44 nm. Accordingly, the dual-band SPR spectrum is situated in the UV–Vis spectra validating the non-spherical shape of Ag NPs. The functional group present on the Ag NPs surface was analysed by FT-IR confirms the capping and reducing ability of methanolic PE G. resinifera. Further, the mechanism of antimicrobial activity studied using electron microscope showed the morphological changes with destructed cell walls of E. coli NCIM 2931 and S. aureus NCIM 5021 cells, when they treated with Ag NPs. The Ag NPs were more effective against S. aureus and E. coli with MIC 128 μg/ml as compared to P. aeruginosa NCIM 5029 with MIC 256 μg/ml. Apart from this, the reduction of toxic organic pollutant 4-NP to 4-AP within 20 min reveals the excellent catalytic activity of Ag NPs with rate constant k = 15.69 s^?1.     

Preparation and characterization of novel PES‐(SiO2‐g‐PMAA) membranes with antifouling and hydrophilic properties for separation of oil‐in‐water emulsions

In the present study, modification of nanoparticles (NPs) was investigated to mitigate aggregation of SiO₂ nanoparticles and improve the polymeric membrane's performance. For this purpose, the surface of SiO₂ nanoparticles was activated with amine groups, and polymethacrylic acid (PMAA) was grafted on the surface of NPs by atom transfer radical polymerization. Modified NPs were characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) tests. Polyethersulfone (PES) membranes were fabricated with both SiO₂ and SiO₂‐g‐PMAA NPs via nonsolvent‐induced phase separation method. The fabricated membranes were characterized regarding their permeability, hydrophilicity, and porosity properties, and their separation efficiency was tested using the synthetic oil‐in‐water emulsion. The surface and cross‐sectional morphologies of membranes were observed by field emission scanning electron microscopy (FESEM). The experimental trials showed that modified NPs dispersed more uniformly in the structure of membranes and hydroxyl groups on the surface of NPs acted more effectively. Modification of NPs enhance the membrane performance in terms of permeate flux, hydrophilicity, and porosity. NPs modification improved the permeate flux about 46%. Oil rejection for all tested membranes was more than 98%, and modification of NPs did not reduce the rejection of membranes. The optimum concentration was obtained as 1 wt.% and 1.5 wt.% for SiO₂ and SiO₂‐g‐PMAA, respectively. Aggregation effect dominated at concentrations beyond the optimum values that decreased the permeate flux, consequently.     

Novel Pyrazoline‐based Organometallic Compounds Containing Ferrocenyl and Quinoline units: Synthesis,Characterization and Microbial susceptibilities

Some novel pyrazoline‐based organometallic compounds were synthesized as new leads in antimicrobial chemotherapy. The structures of compounds were elucidated by different spectroscopic techniques and elemental analyses. All compounds were investigated for in vitro antimicrobial studies against fifteen ATTC bacterial and fungal strains. The microbial susceptibility of these compounds revealed that all the tested compounds gave good minimum inhibitory concentration (MIC) values against the tested organisms that are either similar or even better than the reference drugs amoxicillin and fluconazole, which gave MIC values 8‐64 μg/ml against bacterial and 64 μg/ml against fungal strains, respectively. Among all compounds, compound ( 4d ) 1‐(5‐(4‐chlorophenyl)‐3‐ferrocenyl‐4,5‐dihydropyrazol‐1‐yl)‐2‐quinolin‐8‐yloxy) ethanone, emerged out the most promising antimicrobial organometallic derivative with MIC values against all the strains ranging from 8‐32 μg/ml. Other compounds gave a range of MIC values between 16‐64 μg/ml against S. bovis, 16‐32 μg/ml against E. coli, and C. tropicalis except compound ( 4d) which gave MIC 8 μg/ml against S. bovis and E. coli, whereas 32 μg/ml against C. tropicalis. Collectively, these compounds gave a lower MIC value between 32‐64 μg/ml against both of the biofilm forming strains namely, P. aeruginosa and S. mutans. The results of microbial susceptibility concluded that these novel organometallic compounds are new leads in antimicrobial chemotherapy and can be very useful for further optimization work on microbial chemotherapy.     

Anodic composite deposition of RuO2·xH2O–TiO2 for electrochemical supercapacitors

This communication demonstrates the first work on anodic composite deposition of oxide nanocomposites. Rutile TiO₂ nanoflowers with an average petal size of ca. 10 nm in diameter and 100 nm in length were synthesized from a TiCl₃ solution purged with air at 25 °C for 12 days prior to the composite deposition. Hydrous ruthenium oxide (RuO₂·xH₂O) and TiO₂ nanoflowers were composite-deposited onto Ti substrates for supercapacitors. In comparing with RuO₂·xH₂O deposits, RuO₂·xH₂O–TiO₂ nanocomposites with a highly porous nature exhibit the weakly mass-dependent specific capacitance and high-power capacitive characteristics.     

Fabrication of Au‐Nanoparticle/TiO2‐Nanotubes Electrodes Using Electrochemical Methods and Their Application for Electrocatalytic Oxidation of Hydroquinone

Gold nanoparticle (Au‐NPs)‐Titanium oxide nanotube (TiO₂‐NTs) electrodes are prepared by using galvanic deposition of gold nanoparticles on TiO₂‐NTs electrodes as support. Scanning electron microscopy and energy‐dispersive X‐ray spectroscopy results indicate that nanotubular TiO₂ layers consist of individual tubes of about 60–90 nm diameters and gold nanoparticles are well‐dispersed on the surface of TiO₂‐NTs support. The electrooxidation of hydroquinone of Au‐NPs/TiO₂‐NTs electrodes is investigated by different electrochemical methods. Au‐NPs/TiO₂‐NTs electrode can be used repeatedly and exhibits stable electrocatalytic activity for the hydroquinone oxidation. Also, determination of hydroquinone in skin cream using this electrode was evaluated. Results were found to be satisfactory and no matrix effects are observed during the determination of hydroquinone content of the “skin cream” samples.     

Facile combustion synthesis of Ag2O nanoparticles using cantaloupe seeds and their multidisciplinary applications

Silver oxide nanoparticles (Ag₂O NPs) were prepared using cantaloupe (Cucumis melo) seeds as a fuel by employing a green synthesis method. The prepared Ag₂O NPs were investigated using powder X-ray diffraction (PXRD), UV–visible spectrum, Fourier transform infrared analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy-dispersive spectroscopy, and photoluminescence studies. PXRD data reveal the establishment of cubic crystal structure of Ag₂O NPs. According to SEM and TEM results, the morphology of the prepared NPs was agglomerated and spherical. The photodegradation activity of the prepared Ag₂O NPs over methylene blue dye was promising under visible light irradiation. Furthermore, the antimicrobial assay of the synthesized Ag₂O NPs was carried out by the disc diffusion method against Gram-positive and Gram-negative microbial strains.     

Optimizing adsorptive removal of malachite green and methyl orange dyes from simulated wastewater by Mn‐doped CuO‐Nanoparticles loaded on activated carbon using CCD‐RSM: Mechanism,regeneration, isotherm,kinetic, and thermodynamic studies

In the present work, Mn‐doped CuO‐NPs‐AC was prepared by a simple method, characterized using various techniques such as FESEM, EDX, XRD, PSD, and pH_pzc and finally used for the adsorption of malachite green (MG) and methyl orange (MO) in a number of single and binary solutions. A series of adsorption experiments were conducted to investigate and optimize the influence of various factors (such as different pH, concentration of MG and MO, adsorbent mass, and sonication time) on the simultaneous adsorption of MG and MO using response surface methodology. Under optimal conditions of pH 10, adsorbent dose of 0.02 g, MG concentration of 30 mg L^?1, MO concentration of 30 mg L^?1, and sonication time of 4.5 min at room temperature, the maximum predicted adsorption was observed to be 100.0%, for both MG and MO, showing that there is a favorable harmony between the experimental data and model predictions. The adsorption isotherm of MO and MG by Mn‐doped CuO‐NPs‐AC could be well clarified by the Langmuir model with maximum adsorption capacity of 320.69 mg g^?1 and 290.11 mg g^?1 in the single solution and 233.02 mg g^?1 and 205.53 mg g^?1 in the binary solution by 0.005 g of adsorbent mass for MG and MO, respectively. Kinetic studies also revealed that both MG and MO adsorption were better defined by the pseudo‐second order model for both solutions. In addition, the thermodynamic constant studies disclosed that the adsorption of MG and MO was likely to be influenced by a physisorption mechanism. Eventually, the reusability of the Mn‐doped CuO‐NPs‐AC after six times showed a reduction in the adsorption percentage of MG and MO.     

Synthetic and antimicrobial studies on new gold(I) complexes of imidazolidin‐2‐ylidenes

Six new 1,3‐diorganylimidazolidin‐2‐ylidene (NHC) gold(I) complexes of the type [Au(NHC)₂]⁺ (1–6), were synthesized by reacting [AuCl(PPh)₃] with 1,3‐dimesitylimidazolidin‐2‐ylidene or bis(1,3‐dialkylimidazolidin‐2‐ylidene). The complexes 1–6 were fully characterized by elemental analyses and spectroscopic data. The placement of mesityl or para‐substituted benzyl groups on the nitrogen atoms of the ring of the complexes leads to the particularly active antibacterial agents evaluated in this work. It is worth noting that the p‐methoxybenzyl derivative (2) inhibited the growth of Pseudomona aeruginosa, Staphylococcus epidermidis, Staphylococcus aureus and Enterococcus faecalis with minimum inhibitory concentration (MIC) values of 3.12 µg ml^?1, 6.25 µg ml^?1, 3.12 µg ml^?1 and 3.12 µg ml^?1 respectively. In contrast, the analogous p‐dimethylaminobenzyl derivative (3) is effective only against Escherichia coli (MIC = 3.12 µg ml^?1). Copyright © 2004 John Wiley & Sons, Ltd.     

Synthesis of CuS nanoparticles loaded on activated carbon composite for ultrasound‐assisted adsorption removal of dye pollutants: Process optimization using CCD‐RSM,equilibrium and kinetic studies

In this study, the CuS nanoparticles loaded on activated carbon (CuS‐NPs‐AC) composite was synthesized and then, characterized by XRD and FE‐SEM analyses. The prepared composite was used as a potential adsorbent for the simultaneous ultrasound‐assisted removal of Indigo Carmine (IC) and Safranin‐O (SO). The CuS‐NPs‐AC dose (0.01‐0.03 g), sonication time (1‐5 min), initial SO concentration (5‐15 mg L^‐1) and initial IC concentration (5‐15 mg L^‐1) as expectable effective parameters were studied by central composite design (CCD) under response surface methodology (RSM) to obtain an useful knowledge about the effect of simultaneous interaction between IC and SO on their removal percentage. The optimum SO and IC removal percentages were determined to be 98.24 and 97.15% at pH = 6, 0.03 g of the CuS‐NPs‐AC, 3 min sonication time, 12 and 10 mg L^‐1 of IC and SO. The values of coefficient of determination (R²) for SO and IC were 0.9608 and 0.9796, respectively, indicating the favorable fitness of the experimental data to the second order polynomial regression model. The isotherm data were well correlated with Freundlich model. The maximum monolayer adsorption capacities of 87.5 and 69.90 mg g^‐1 at room temperature for IC and SO in the investigated binary system expressed the high efficiency of the novel adsorbent for water cleanup within a short time. The investigation of correlation between time and rate of adsorption revealed that IC and SO adsorption onto the CuS‐NPs‐AC followed pseudo‐second‐order and intra‐particle diffusion simultaneously.     

Efficient Synthesis of Novel 3‐Phenyl‐5‐thioxo‐3,4,5,6‐tetrahydroimidazo[4,5‐c]pyrazole‐2(1H)‐carbothioamide Derivatives Using a CeO2–MgO Catalyst and Evaluation of Antimicrobial Activity

Imidazo[4,5‐c ]pyrazole derivatives ( 3a–f , 4a–f , and 5a–f ) were efficiently synthesized by one‐pot three‐component reactions using CeO₂–MgO as the catalyst. The synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, and mass spectroscopic analyses. The in vitro antimicrobial activity of the synthesized compounds against various bacterial and fungal strains was screened. Compound 3b was highly active [minimum inhibitory concentration (MIC): 0.5 μg/mL] against Gram‐positive Staphylococcus aureus , and compounds 3b , 3f , 4d , and 4e were highly active (MIC: 0.5, 2, 2, and 0.5 μg/mL, respectively) against Gram‐negative Pseudomonas aeruginosa and Klebsiella pneumoniae , relative to standard ciprofloxacin in the antibacterial activity screening. Compounds 3b and 4f were highly active (MIC: 4 and 0.5 μg/mL, respectively) against Aspergillus fumigatus and Microsporum audouinii in the antifungal activity screening compared with the clotrimazole standard.     

Arrayed CNx NT–RuO2 nanocomposites directly grown on Ti-buffered Si substrate for supercapacitor applications

Significant enhancement in supercapacitor performance has been achieved via a new RuO₂ nanocomposite materials prepared by direct ruthenium sputtering on arrayed multi-walled carbon nanotubes supported by Ti-buffered Si wafer. XPS, HRTEM and SAED analyses reveal that as-prepared nanoparticles have a crystalline Ru metal core with RuO₂ oxide coating. The nanocomposites convert to RuO₂–CN_x NTs with subsequent electrochemical cycling. At present, well-dispersed and strongly adhered RuO₂ NPs have been densely populated on CN_x NTs to obtain the overall specific capacitance (1380 F/g-RuO₂), charging–discharging rate (up to 600 mV/s) and operation stability (5000 cycles). Thus, RuO₂–CN_x NTs nanocomposites would make a promising candidate for use in next-generation high efficiency miniaturized supercapacitors directly fabricated on Si substrate.     

Synthesis,characterization and release profiles of nanoparticles self‐assembled from poly (PEGMA‐co‐MMA‐co‐acryloyl‐β‐CD) copolymers

A novel amphiphilic copolymer was synthesized from poly (ethylene glycol) methyl ether methacrylate (PEGMA950), methyl methacrylate (MMA) and acryloyl‐β‐cyclodextrin (acryloyl‐β‐CD) using the composites of (NH₄)₂S₂O₈/NaHSO₃ as the oxidation–reduction initiators. The successful fabrication of poly(PEGMA‐co‐MMA‐co‐acryloyl‐β‐CD) copolymers was confirmed by Fourier transform infrared spectrometer (FTIR), ¹H‐nuclear magnetic resonance (¹H NMR) spectra. The amphiphilic copolymer could self‐assemble into nanoparticles (NPs), and their morphology and particle size distribution were characterized with transmission electron microscopy (TEM), atomic force microscope (AFM) and dynamic light scattering (DLS) methods. Ibuprofen (IBU) was encapsulated in the novel NPs, and the release profiles of IBU were investigated. FTIR and ¹H NMR spectra illustrated that the poly(PEGMA‐co‐MMA‐co‐acryloyl‐β‐CD) copolymers were synthesized without any residual monomers and initiators. TEM and AFM photographs suggested that the obtained NPs were spherical, and the DLS results indicated that the diameter of blank NPs was 157.3 ± 32.7 nm. The IBU release profile showed that the IBU‐loaded NPs had certain pH responsibility. Copyright © 2014 John Wiley & Sons, Ltd.     

Triazole‐based ligands functionalized silica: Effects of ligand denticity and donors on catalytic oxidation activity of Pd nanoparticles

Triazole‐based ligands, tris (triazolyl)methanol (Htbtm), bis (triazolyl)‐phenylmethanol (Hbtm), and phenyl (pyridin‐2‐yl)(triazolyl)methanol (Hpytm), with differences in ligand denticity (i.e., bidentate and tridentate) and type of N donors (i.e., triazole and pyridine) were functionalized onto a silica support to produce the corresponding SiO₂‐ L ( L  = tbtm, btm, pytm). Subsequent reactions with Pd (CH₃COO)₂ in CH₂Cl₂ yielded Pd/SiO₂‐ L . ICP‐MS reveals that Pd loadings are higher with increased N loadings, resulting in the following trend: Pd/SiO₂‐tbtm (0.83 mmol Pd g^?1) > Pd/SiO₂‐btm (0.65 mmol Pd g^?1) ~ Pd/SiO₂‐pytm (0.63 mmol Pd g^?1). Meanwhile, TEM images of the used Pd/SiO₂‐ L catalysts after the first catalytic cycle show that the mean size of Pd NPs is highest with Pd/SiO₂‐pytm (8.5 ± 1.5 nm), followed by Pd/SiO₂‐tbtm (6.4 ± 1.6 nm) and Pd/SiO₂‐btm (4.8 ± 1.3 nm). Based on TONs, catalytic studies toward aerobic oxidation of benzyl alcohol to benzaldehyde at 60 °C in EtOH showed that Pd/SiO₂‐pytm possessed the most active surface Pd(0) atoms, most likely as a result of more labile properties of the pyridine–triazole ligand compared to tris‐ and bis (triazolyl) analogs. ICP‐MS and TEM analysis of Pd/SiO₂‐btm indicate minimal Pd leaching and similar average Pd NPs sizes after 1^st and 5^th catalytic runs, respectively, confirming that SiO₂‐btm is an efficient Pd NPs stabilizer. The Pd/SiO₂‐btm catalyst was also active toward aerobic oxidation of various benzyl alcohol derivatives in EtOH and could be reused for at least 7 reaction cycles without a significant activity loss.     

New potential anti-SARS-CoV-2 and anti-cancer therapies of chitosan derivatives and its nanoparticles: Preparation and characterization

Chitosan (CS) is a biopolymer and has reactive amine/hydroxyl groups facilitated its modifications. The purpose of this study is improvement of (CS) physicochemical properties and its capabilities as antiviral and antitumor through modification with 1-(2-oxoindolin-3-ylidene)thiosemicarbazide (3A) or 1-(5-fluoro-2-oxoindolin-3-ylidene)thiosemicarbazide (3B) via crosslinking of poly(ethylene glycol)diglycidylether (PEGDGE) using microwave-assisted as green technique gives (CS-I) and (CS-II) derivatives. However, (CS) derivatives nanoparticles (CS-I NPs) and (CS-II NPs) are synthesized via ionic gelation technique using sodium tripolyphosphate (TPP). Structures of new (CS) derivatives are characterized using different tools. The anticancer, antiviral efficiencies and molecular docking of (CS) and its derivatives are assayed. (CS) derivatives and its nanoparticles show enhancement in cell inhibition toward (HepG-2 and MCF-7) cancer cells in comparison with (CS). (CS-II NPs) reveals the lowest IC₅₀ values are 92.70 ± 2.64 μg/mL and 12.64 µ g/mL against (HepG-2) cell and SARS-CoV-2 (COVID-19) respectively and the best binding affinity toward corona virus protease receptor (PDB ID 6LU7) ?5.71 kcal / mol. Furthermore, (CS-I NPs) shows the lowest cell viability% 14.31 ± 1.48 % and the best binding affinity ?9.98 kcal/moL against (MCF-7) cell and receptor (PDB ID 1Z11) respectively. Results of this study demonstrated that (CS) derivatives and its nanoparticles could be potentially employed for biomedical applications.     

Heterointerface engineering of Ru/RuS2 on N/S-doped hollow mesoporous carbon for promoting alkaline hydrogen evolution

Alkaline hydrogen evolution reaction (HER) suffers from a sluggish kinetic, which requires the elaborate catalytic interface and micro-nanoscale architecture engineering of the electrocatalysts to accelerate the water dissociation and hydrogen evolution. Herein, the heterointerface engineering was proposed for promoting the alkaline HER by constructing the highly exposed Ru/RuS₂ heterostructures homogeneously distributed on hollow N/S-doped carbon microspheres (Ru/RuS₂@h-NSC). Benefited from the synergistic effect of heterointerfacial Ru/RuS₂, the high accessibility of the active sites on both inner and outer surface of mesoporous shells and the efficient mass transport, Ru/RuS₂@h-NSC affords a remarkable catalytic performance with an overpotential of 26 mV@10 mA/cm² for alkaline HER, outperforming most of the state-of-the-art catalysts. Further applying Ru/RuS₂@h-NSC and its oxidized derivate for the overall alkaline water splitting, the required cell voltage is much lower than that of the commercial Pt/C||RuO₂ pair to achieve the same current density. Our study may allow us to guide the design of micro-nanoreactors with optimal catalytic interfaces for promising electrocatalytic applications.     

Five‐coordinate dinuclar cobalt (II), copper (II), zinc (II) and cadmium (II) complexes with 4‐bromo‐N‐(2‐pyridinylmethylene)benzenamine: Synthesis,characterisation and methyl methacrylate polymerization

A series of late transition metal complexes, [(bpma)Co(μ – Cl)Cl] ₂ , [(bpma)Cu(μ – Cl)Cl] ₂ , [(bpma)Zn(μ – Cl)Cl] ₂ and [(bpma)Cd(μ – Br)Br] ₂ (where bpma is 4‐bromo‐N‐((pyridin‐2‐yl)methylene)benzenamine) have been synthesized and structurally characterized. The X‐ray structures of dimeric complexes [(bpma)M(μ – X)X] ₂ (M = Co, Cu and Zn, X = Cl; M = Cd, X = Br) showed a distorted 5‐coordinate trigonal bipyramidal geometry involving two nitrogen atoms of N,N‐bidentate ligand, two bridged and one terminal halogen atoms. The complex [(bpma)Cu(μ – Cl)Cl] ₂ revealed the highest catalytic activity for the polymerisation of methyl methacrylate in the presence of modified methylaluminoxane with an activity of 9.14 × 10⁴ g PMMA/mol·Cu·h at 60 °C and afforded syndiotactic poly (methylmethacrylate) (rr = 0.69).